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NATIONAL INSTITUTE ON DEAFNESS AND OTHER COMMUNICATION DISORDERS
STATEMENT OF DR. JAMES B. SNOW, JR., DIRECTOR
Senator HARKIN. Dr. Snow, your budget request of $146.3 million is 8.4 percent above 1991.
We are now close to your first anniversary as the first Director of the National Institute on Deafness and Other Communication Disorders. The committee is delighted to have you back here with us today, and please proceed with your statement.
Dr. SNOW. Thank you very much, Senator. It is a privilege to be here before the committee to discuss the programs of the National Institute on Deafness and Other Communication Disorders.
In the past 22 years since the creation of the Institute, we have seen an increased vigor in part of the scientific community. There has been an outpouring of very high quality applications to our Institute. We received 254 applications in 1989, 350 in 1990, and 472 this year, and we conservatively estimate that there will be 546 in 1992. And this represents an increase of over 100 percent since 1989.
As we discussed last year, 1 in 1,000 infants are born deaf, and 50 percent of those have a cause that is attributable to a genetic defect. Just yesterday, I learned from the Waardenburg syndrome consortium that we organized and support that they have now located the gene within one centiMorgan on chromosome 2, and this is an important breakthrough in hereditary deafness.
REGENERATION OF SENSORY CELLS
We are also making progress in understanding the regeneration of sensory cells, unlocking ways to accelerate their repair and return to normal function. This progress has resulted from the study of avian auditory and balance related hair cells. The research has stimulated the hope that similar mechanisms can be initiated in mammals and ultimately in humans leading to the ability to reverse acquired hearing loss.
The olfactory neuroepithelium is known to have a remarkable capability of regenerating olfactory receptor neurons throughout life. The olfactory neuroepithelium also produces another cell that migrates into the brain during adult life, and we are supporting scientists studying the characteristics of these cells and defining the limits of their migration.
The early identification of hearing loss in infants is critical to language acquisition and development. The NIDCD is searching for reliable and cost-effective ways to reduce the average age of diag
nosis of hearing impairment in infants from the current 21⁄2 years to the first several months of life.
The NIDCD has made major investments in the development and improvement of multichannel cochlear implants, including a new interleaved-pulse speech processor capable of sampling speech at high rates. This processor provides impressive gains in understanding speech so important to these individuals. Scientists studying the sense of smell have found an indication that some forms of Parkinson's disease and Alzheimer's disease are caused by environmental agents that enter the brain through the olfactory nerve.
The NIDCD will continue to support minority-related research and minority scientists. In several NIDCD-supported clinical trials on otitis media, specific attention has been devoted to minority populations.
Although all clinical trials, supported by the NIDCD include both males and females, recent findings indicate that there are diseases affecting women differentially including Meniere's disease, otosclerosis, and voice tremor.
This budget request places emphasis on basic research to improve our understanding of human communication while supporting clinical trials for prevention, therapeutic intervention, and the development of devices that will improve the quality of the lives of those who already are experiencing the challenges of communication disorders.
Mr. Chairman, the fiscal year 1992 budget request is for $146,321,000.
I will be pleased to try to answer any questions you have. [The statement follows:]
STATEMENT OF DR. JAMES B. SNOW, JR.
It is a privilege to appear before this Committee as the Director of the National Institute on Deafness and Other Communication Disorders (NIDCD). In the past two and a half years since the Institute was created, we have witnessed an increased vigor in the pursuit of answers to questions about the nature of human communication. The NIDCD has supported research and research training on both the normal and disordered functions of hearing, balance, smell, taste, voice, speech and language primarily through investigator-initiated research and by supporting mechanisms of research training designed to encourage scientists to work on the challenging problems confronting this field. The NIDCD continues to monitor its progress through close attention to and scheduled updating of the National Strategic Research Plan and by fostering critically needed basic research to improve our understanding of human communication while supporting research protocols for prevention, therapeutic intervention and development of devices that will improve the quality of life for those who already have communication
Approximately 2 million persons are
One in one thousand infants is born deaf. profoundly deaf. Forty to sixty percent of profound neonatal deafness can be attributed to genetic causes. More than 50 different forms of hereditary deafness are known. The NIDCD has made important progress on two forms of hereditary deafness, Usher syndrome and Waardenburg syndrome. NIDCD investigators have recently located the Usher type 2 gene on chromosome 1 and have begun to fine map and to clone and characterize the gene. A team of scientists in the NIDCD Intramural Research Program and a network of clinicians are at work studying Waardenburg syndrome. Geneticists, otolaryngologists and audiologists throughout the country have been enlisted to bring together intramural scientists and families with hearing loss due to Waardenburg syndrome who would like to participate in the Initially, the focus will be on the mapping of the gene involved in Waardenburg syndrome. This information can be used subsequently to improve diagnosis and genetic counseling and eventually may lead to gene therapy for syndromes of hereditary deafness.
Basic scientists supported by NIDCD are continuing to make important progress on understanding the regeneration of sensory cells, unlocking the ways to accelerate their repair and return to normal function. This progress has resulted from the study of auditory and balance-related hair cells in birds. The research has stimulated hope that similar mechanisms can be initiated in mammals and, ultimately, humans, leading to the ability to reverse acquired hearing loss. Other
important NIDCD supported basic research has demonstrated that the olfactory neuroepithelium, located in the roof of the nose is known to have the remarkable capability of regenerating olfactory receptor neurons throughout life. The olfactory neuroepithelium produces another type of cell that migrates into the brain during adult life. Using both transplants and explants, scientists are now identifying the characteristics of these cells and defining the limits of their migration. The olfactory neuroepithelium is not only a source of olfactory receptor neurons, which have a powerful chemical trophic effect on the brain, but may also be a direct source of additional migratory cells for the brain.
Noise-induced hearing loss is the most common preventable cause of hearing loss and remains of great concern to the Institute. As a result of a NIDCDsponsored Consensus Development Conference on Noise and Hearing Loss, the Institute is engaged in an ongoing public education campaign. The first year of this effort to increase public awareness will be designed to reach intermediate elementary school children about high-risk activities.
The NIDCD recommends screening infants for hearing impairment; screening children prior to entering school; screening adolescents in the late teenage years when otosclerosis may set in; and, in the sixth decade of life, screening adults for presbycusis.
Early identification of hearing loss in infants is critical to language acquisition and development.
NIDCD will sponsor a conference on reliable and costeffective ways of reducing the average age of diagnosis of hearing impairments in infants from the current two and one half years to the first several months of life. In addition, investigators are currently attempting to identify other factors present at age two which place a child at risk for long-term delay in talking. This research may identify which toddlers will benefit most from early,
The most common cause of progressive, conductive hearing loss in the adult with a normal eardrum is otosclerosis. An NIDCD-sponsored physician-scientist has found that a class of drugs, biphosphonates, act effectively to inhibit bone remodeling.
If shown to be effective, these drugs could be used to prevent the onset of otosclerosis or to arrest the progression of the disease in persons who already have it.
Research is now in progress to correlate age-related hearing loss with alterations in neurotransmitter levels. Ultimately, this research may make it possible to delay the onset of presbycusis. Presbycusis is estimated to affect half of all persons between 51 and 91 years of age.